Linear motors are known in the art. According to a typical configuration, a linear motor includes an armature (sometimes referred to as a forcer), the armature including a yoke made up of a pack of ferromagnetic laminations. The yoke includes a plurality of teeth arranged at a predefined pitch, with a plurality of slots respectively separating the teeth. The armature further includes coil windings wound around the teeth and housed in the respective slots.
Linear motors also typically include a magnetic stator (sometimes referred to as a track or rail). The magnet track includes a plurality of plate-like permanent magnets positioned linearly along the track at a predefined pitch with corresponding gaps therebetween. The armature travels along the length of the magnet track with the teeth of the armature adjacent the magnets. The position of the armature is determined via a sensor, and a controller controls the current provided to the coil windings based on the armature position. In this manner, the armature may be selectively driven back and forth along the magnet rail.
While the exemplary linear motor is described with the armature arranged on the moving member and the magnets arranged on the track, it should be appreciated that the configuration may be swapped. For example, the armature may be arranged on the track and the magnets may be arranged on the moving member.
Linear motors such as those described above are quite useful in a variety of applications. These applications include, but are not limited to, control systems, manufacturing processes, robotics, etc. Linear motors provide precision linear movement in a whole host of applications.
Despite the recognized advantages associated with known linear motors, there have been a number of drawbacks. For example, when traveling on curved sections of track it is desirable for the linear motor exhibit performance similar to that when traveling on straight sections of track. However, conventional linear motors do not exhibit such performance, and instead have reduced performance on the curved sections of track.
Thus, a need exists for a linear motor that provides similar performance on both straight and curved portions of track.